CA1266269A - Process for the preparation of aliphatic tertiary amines - Google Patents
Process for the preparation of aliphatic tertiary aminesInfo
- Publication number
- CA1266269A CA1266269A CA000525557A CA525557A CA1266269A CA 1266269 A CA1266269 A CA 1266269A CA 000525557 A CA000525557 A CA 000525557A CA 525557 A CA525557 A CA 525557A CA 1266269 A CA1266269 A CA 1266269A
- Authority
- CA
- Canada
- Prior art keywords
- palladium
- weight
- catalyst
- amines
- formaldehyde
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D295/00—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms
- C07D295/02—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms containing only hydrogen and carbon atoms in addition to the ring hetero elements
- C07D295/023—Preparation; Separation; Stabilisation; Use of additives
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
- C07C209/68—Preparation of compounds containing amino groups bound to a carbon skeleton from amines, by reactions not involving amino groups, e.g. reduction of unsaturated amines, aromatisation, or substitution of the carbon skeleton
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Aliphatic tertiary amines are prepared from primary or secondary amines by reaction with formaldehyde, and the N-methyl-olamines so formed are hydrogenated at temperatures of 50° to 200°C
and pressures of 0.1 to 10 MPa in the presence of finely distributed palladium or catalysts containing palladium. The aliphatic tertiary amines produced according to the present invention are valuable intermediate products in the synthesis of pharmaceuticals, catalysts for the production of polyurethanes, bactericides, dye intensification agents, and deceleration agents.
Aliphatic tertiary amines are prepared from primary or secondary amines by reaction with formaldehyde, and the N-methyl-olamines so formed are hydrogenated at temperatures of 50° to 200°C
and pressures of 0.1 to 10 MPa in the presence of finely distributed palladium or catalysts containing palladium. The aliphatic tertiary amines produced according to the present invention are valuable intermediate products in the synthesis of pharmaceuticals, catalysts for the production of polyurethanes, bactericides, dye intensification agents, and deceleration agents.
Description
~ 2 ~ 9 Process for the Preparation of Aliphatic Tertiary Amines The invention relates to a process for the preparation of tertiary amines by reaction of primary or secondary amines with formaldehyde, and subsequent hydrogenation of the intermediate N-methylolamines in the presence of palladium catalaysts at elevated pressure and elevated temperature.
Tertiary amines are used in many applications.
They àre, for example, valuable intermediate products in the synthesis of pharmaceuticals, catalysts for the manufacture of polyurethanes, bactericides, dye intensification agents, and deceleration agents.
Various processes for the preparation of tertiary amines by the catalytic hydrogenation of the corresponding N-methylol compounds are known. The main differences between them are the kind of hydrogenation catalysts employed and the reaction conditions to be observed. Nickel or cobalt catalysts, in particular in the form of Raney metals or mixed catalysts of nickel, cobalt and additives of manganese or molybdenum, are used ` in the reaction. They require temperatures of 40 to 200C and pressures of 0.35 to 20 MPa. A disadvantage of these catalysts is their high hydrogenation activity.
This causes the alkyl groups contained in the amine to be split off from the nitrogen atom of the amine. Thus, secondary and primary amines are formed as well as amines which, through transalkylation, are of a different composition from those desired.
Other processes use copper catalysts; e.g. copper chromite. These generally less activ~ hydrogenation catalysts require higher pressures and temperatures and thus more energy and more elaborate apparatus.
Furthermore, all these catalysts often have to be used in substantial concentrations which causes problems in the separation of the reaction product from the catalyst. It is also known that precious metal catalysts can be used for the hydrogenation of aromatically bound N-methylol groups as well as for the preparation of dimethylamino acids (cf. Houben-Weyl, Methoden der org. Chemie, Band II/l, pages 641 and 642).
Therefore, the problem consisted of finding a process for the preparation oE tertiary amines which is easy to perform in technical terms, insures high yields, and permits simple separation of the reaction product from the catalyst. The solution is a process for the preparation of aliphatic tertiary amines by the reaction of primary or secondary amines with formaldehyde and subsequent catalytic hydrogenation of the N-methylolamines thus formed a~ elevated temperature and elevated pressure. It is characterized in that hydrogenation catalysts containing palladium are employed. The process according to the invention has the advantage that the majority of the methylol compounds are converted to their corresponding metbyl compounds without primary or secondary amines being formed.
Primary or secondary, aliphatic or cycloaliphatic amines and, in addition, aliphatic or cycloaliphatic diamines, hydroxyamines and etheramines are employed as starting materials. The aEore-mentioned amines may contain up to 20 carbon atoms and, in particular, up to 12 carbon atoms. The secondary amine groups can also be part of a hydrocyclic ring system, in particular one containing 5 to 7 ring members. Suitable amines are, for example, ethylamine, propylamine, butylamine, 2-ethylhexylamine, cyclohexylamine, dibutylamine, dimethylaminopropylamine, dicyclohexylamine, morpholine, piperidine and piperazine.
It has proved advantageous to use formaldehyde as a concentrated aqueous solution; e.g. as a 25 to 44%
solutionO However, it can also be used in its polymer forms; e.g. as paraformaldehyde.
The amines and the formaldehyde are reacted in stoichiometric ratios; i.e., 1 mol formaldehyde is employed per methyl group to be introduced. About 5 to 10% excess of formaldehyde is advantsgeous.
The amine and formaldehyde can initially be made to react. The reaction takes place at atmospheric pressure at temperatures between 0 and 100C, preferably 40 to 90C. In the second stage, the N-methylol compound obtained is hydrogenated at temperatures of 50 to 200C, preferably 80 to 150C, and pressures of 0.1 to 10 MPa, preferably 1 to 5 MPa.
According to a preferred one-stage embodiment of the process according to the invention, aqueous formaldehyde solution is added continuously to the amine and the catalyst. According to another preferred one-stage embodiment, the amine, paraformaldehyde and catalyst are charged into the reaction vessel and hydrogen is introduced into the mixture. In both cases the reaction is carried out under hydrogenation conditions;
i.e. at temperatures between 50 and 200C, preferably 80C to 150C., and pressures of 0.1 to lO MPa, preferably l to 5 MPa.
The methylation of amines according to the new procedure takes place in the presence of palladium catalysts. The palladium can be employed in finely distributed form directly as the metal. However, it is particularly advantageous to apply the metal to a carrier;
e.g. activa~ed carbon. It is especially advantageous if the carrier catalysts contain 0.2 to 20% by wei~ht, preferably 1 to 10% by weight, palladium, based on the catalyst mass. In addition, activators can also be present. The catalysts are prepared by impregnating the carrier with hydrochloric palladium solution.
The catalysts are highly active. Therefore, they can be used in extremely low concentrations. Based on the primary or secondary amine starting materials, preferably only 0.01 to 0.05% by weight palladium is employed as a finely distributed metal or fixed on a carrier.
The small amount of catalyst used requires no complicated filtration ~or the separation thereof from the reaction product. Nearly all the catalyst can be recovered and recycled more than 20 times in discontinuous operations without any reduction in activity during the lS methylation reaction. The tertiary amines are obtained from the reaction mixture by fractional distillation. It is advantageous to remove the water present in the reaction mixture by azeotropic distillation or by dehydration with sodium hydroxide.
In the ~ollowing examples the process according to the invention is described in more detail.
Example 1 2040 g S20 mol) dimethylaminopropylamine and lO g of a palladium/activated-carbon catalyst (Pd content: 5%
by weight, corresponding to 0.025% by weight, based on the amine employed) are placed in a 10 litre agitator autoclave and heated to 100C at a hydrogen pressure of
Tertiary amines are used in many applications.
They àre, for example, valuable intermediate products in the synthesis of pharmaceuticals, catalysts for the manufacture of polyurethanes, bactericides, dye intensification agents, and deceleration agents.
Various processes for the preparation of tertiary amines by the catalytic hydrogenation of the corresponding N-methylol compounds are known. The main differences between them are the kind of hydrogenation catalysts employed and the reaction conditions to be observed. Nickel or cobalt catalysts, in particular in the form of Raney metals or mixed catalysts of nickel, cobalt and additives of manganese or molybdenum, are used ` in the reaction. They require temperatures of 40 to 200C and pressures of 0.35 to 20 MPa. A disadvantage of these catalysts is their high hydrogenation activity.
This causes the alkyl groups contained in the amine to be split off from the nitrogen atom of the amine. Thus, secondary and primary amines are formed as well as amines which, through transalkylation, are of a different composition from those desired.
Other processes use copper catalysts; e.g. copper chromite. These generally less activ~ hydrogenation catalysts require higher pressures and temperatures and thus more energy and more elaborate apparatus.
Furthermore, all these catalysts often have to be used in substantial concentrations which causes problems in the separation of the reaction product from the catalyst. It is also known that precious metal catalysts can be used for the hydrogenation of aromatically bound N-methylol groups as well as for the preparation of dimethylamino acids (cf. Houben-Weyl, Methoden der org. Chemie, Band II/l, pages 641 and 642).
Therefore, the problem consisted of finding a process for the preparation oE tertiary amines which is easy to perform in technical terms, insures high yields, and permits simple separation of the reaction product from the catalyst. The solution is a process for the preparation of aliphatic tertiary amines by the reaction of primary or secondary amines with formaldehyde and subsequent catalytic hydrogenation of the N-methylolamines thus formed a~ elevated temperature and elevated pressure. It is characterized in that hydrogenation catalysts containing palladium are employed. The process according to the invention has the advantage that the majority of the methylol compounds are converted to their corresponding metbyl compounds without primary or secondary amines being formed.
Primary or secondary, aliphatic or cycloaliphatic amines and, in addition, aliphatic or cycloaliphatic diamines, hydroxyamines and etheramines are employed as starting materials. The aEore-mentioned amines may contain up to 20 carbon atoms and, in particular, up to 12 carbon atoms. The secondary amine groups can also be part of a hydrocyclic ring system, in particular one containing 5 to 7 ring members. Suitable amines are, for example, ethylamine, propylamine, butylamine, 2-ethylhexylamine, cyclohexylamine, dibutylamine, dimethylaminopropylamine, dicyclohexylamine, morpholine, piperidine and piperazine.
It has proved advantageous to use formaldehyde as a concentrated aqueous solution; e.g. as a 25 to 44%
solutionO However, it can also be used in its polymer forms; e.g. as paraformaldehyde.
The amines and the formaldehyde are reacted in stoichiometric ratios; i.e., 1 mol formaldehyde is employed per methyl group to be introduced. About 5 to 10% excess of formaldehyde is advantsgeous.
The amine and formaldehyde can initially be made to react. The reaction takes place at atmospheric pressure at temperatures between 0 and 100C, preferably 40 to 90C. In the second stage, the N-methylol compound obtained is hydrogenated at temperatures of 50 to 200C, preferably 80 to 150C, and pressures of 0.1 to 10 MPa, preferably 1 to 5 MPa.
According to a preferred one-stage embodiment of the process according to the invention, aqueous formaldehyde solution is added continuously to the amine and the catalyst. According to another preferred one-stage embodiment, the amine, paraformaldehyde and catalyst are charged into the reaction vessel and hydrogen is introduced into the mixture. In both cases the reaction is carried out under hydrogenation conditions;
i.e. at temperatures between 50 and 200C, preferably 80C to 150C., and pressures of 0.1 to lO MPa, preferably l to 5 MPa.
The methylation of amines according to the new procedure takes place in the presence of palladium catalysts. The palladium can be employed in finely distributed form directly as the metal. However, it is particularly advantageous to apply the metal to a carrier;
e.g. activa~ed carbon. It is especially advantageous if the carrier catalysts contain 0.2 to 20% by wei~ht, preferably 1 to 10% by weight, palladium, based on the catalyst mass. In addition, activators can also be present. The catalysts are prepared by impregnating the carrier with hydrochloric palladium solution.
The catalysts are highly active. Therefore, they can be used in extremely low concentrations. Based on the primary or secondary amine starting materials, preferably only 0.01 to 0.05% by weight palladium is employed as a finely distributed metal or fixed on a carrier.
The small amount of catalyst used requires no complicated filtration ~or the separation thereof from the reaction product. Nearly all the catalyst can be recovered and recycled more than 20 times in discontinuous operations without any reduction in activity during the lS methylation reaction. The tertiary amines are obtained from the reaction mixture by fractional distillation. It is advantageous to remove the water present in the reaction mixture by azeotropic distillation or by dehydration with sodium hydroxide.
In the ~ollowing examples the process according to the invention is described in more detail.
Example 1 2040 g S20 mol) dimethylaminopropylamine and lO g of a palladium/activated-carbon catalyst (Pd content: 5%
by weight, corresponding to 0.025% by weight, based on the amine employed) are placed in a 10 litre agitator autoclave and heated to 100C at a hydrogen pressure of
2 MPa. Then 3570 g of a solution of formaldehyde in water (37% by weight formaldehyde, based on the solution and corresponding to ~4 mol formaldehyde) are added over a period of 3 hours. From the very beginning of the addition, a continuous gas absorption is observed (about 0.4 MPa/15 minutes) which necessitates continuous replacement of the hydrogen to maintain the pressure at 2.0 MPa. One hour after the addition of the formaldehyde has been completed, the reactor is cooled and the reaction product is removed and examined with a gas chromatograph.
The dimethylaminopropylamine is completely reacted. After dehydration and distillation, 2342 g N,N,N' ,N'-tetramethyl~
1,3-diaminopropane is obtained, corresponding to a yield of 90.1% of theoretical.
Example 2 36~0 g dicyclohexylamine (20 mol), 960 g (32 mol) paraformaldehyde and 18 g of the catalyst used in Example 1 (corresponding to 0.025% by weight palladium, based on the amine used) are placed in a 10 litre agitator autoclave. The mixture is stirred for 8 hours at 130C
and 2.0 MPa pressure, the absorbed hydrogen being replaced. After the product has been cooled, it is examined with a gas chromatograph. Only traces of the ,t~ 3 starting amine used can be detected. ~fter distillation, 3779 g N-methyl-dicyclohexylamine is obtained, corresponding to a yield of 97.4% of theoretical.
Example 3 ; 5 1720 g piperazine (20 mol) is dissolved in 860 g methanol in a 10 litre agitator autoclave. After 17.2 g of the catalyst used in the other examples has been added (corresponding to 0.05% by weight palladium, based on the amine employed), the solution is heated to 100C and a hydrogen pressure of 2.0 MPa is maintained. Then 2992 g (44 mol) of a solution of formaldehyde in water (44% by weight formaldehyde based on the solution) is added continuously over a period of 3 hours, the hydrogen pressure being kept constant by means of a control valve.
~ter cooling, removal of water, and distillation, 2175 g 1.4 dimethylpiperazine is obtained, which is 95.4% of theoretical.
The dimethylaminopropylamine is completely reacted. After dehydration and distillation, 2342 g N,N,N' ,N'-tetramethyl~
1,3-diaminopropane is obtained, corresponding to a yield of 90.1% of theoretical.
Example 2 36~0 g dicyclohexylamine (20 mol), 960 g (32 mol) paraformaldehyde and 18 g of the catalyst used in Example 1 (corresponding to 0.025% by weight palladium, based on the amine used) are placed in a 10 litre agitator autoclave. The mixture is stirred for 8 hours at 130C
and 2.0 MPa pressure, the absorbed hydrogen being replaced. After the product has been cooled, it is examined with a gas chromatograph. Only traces of the ,t~ 3 starting amine used can be detected. ~fter distillation, 3779 g N-methyl-dicyclohexylamine is obtained, corresponding to a yield of 97.4% of theoretical.
Example 3 ; 5 1720 g piperazine (20 mol) is dissolved in 860 g methanol in a 10 litre agitator autoclave. After 17.2 g of the catalyst used in the other examples has been added (corresponding to 0.05% by weight palladium, based on the amine employed), the solution is heated to 100C and a hydrogen pressure of 2.0 MPa is maintained. Then 2992 g (44 mol) of a solution of formaldehyde in water (44% by weight formaldehyde based on the solution) is added continuously over a period of 3 hours, the hydrogen pressure being kept constant by means of a control valve.
~ter cooling, removal of water, and distillation, 2175 g 1.4 dimethylpiperazine is obtained, which is 95.4% of theoretical.
Claims (20)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS
1. A process for the preparation of aliphatic tertiary amines by the reaction of primary and/or secondary amines with formaldehyde and the subsequent catalytic hydrogenation of the N-methylolamines formed at elevated temperature and elevated pressure, wherein palladium hydrogenation catalysts are used.
2. The process of Claim 1 wherein said catalyst contains finely distributed palladium.
3. The process of Claim l wherein hydrogenation takes place at temperatures of 50° to 200°C and pressures of 0.1 to 10 MPa.
4. The process of Claim 2 wherein said hydrogenation takes place at a temperature of 50° to 200°C and pressures of 0.1 to 10 MPa.
5. The process of Claim 1 wherein said hydrogenation takes place at a temperature of 80° to 150°C and pressures of 0.1 to 10 MPa.
6. The process of Claim 1 wherein the catalyst contains 0.2 to 20% by weight based on the catalyst mass.
7. The process of Claim 3 wherein the catalyst contains 0.2 to 20% palladium by weight, based on the catalyst mass.
8. The process of Claim 4 wherein the catalyst contains 0.2 to 20% palladium by weight, based on the catalyst mass,
9. The process of Claim 5 wherein the catalyst contains 0.2 to 20% palladium by weight, based on the catalyst mass.
10. The process of Claim l wherein the catalyst contains 1 to 10% palladium by weight, based on the catalyst mass
11. The process of Claim 3 wherein the catalyst contains 1 to 10% palladium by weight, based on the catalyst mass
12. The process of Claim 4 wherein the catalyst contains 1 to 10% palladium by weight, based on the catalyst mass
13. The process of Claim 5 wherein the catalyst contains 1 to 10% palladium by weight, based on the catalyst mass
14. The process of Claim 1 wherein 0.01 to 0.05% by weight palladium based on said amines is employed as a finely distributed metal or fixed on a carrier.
15. The process of Claim 2 wherein 0.01 to 0.05% by weight palladium based on said amines is employed as a finely distributed metal or fixed on a carrier.
16. The process of Claim 3 wherein 0.01 to 0.05% by weight palladium based on said amines is employed as a finely distributed metal or fixed on a carrier.
17. The process of Claim 4 wherein 0.01 to 0.05°% by weight palladium based on said amines is employed as a finely distributed metal or fixed on a carrier.
18. The process of Claim 5 wherein 0.01 to 0.05% by weight palladium based on said amines is employed as a finely distributed metal or fixed on a carrier.
19. The process of Claim 1 wherein formaldehyde is continuously added as an aqueous solution to the amine and the catalyst.
20. The process of Claim 2 wherein formaldehyde is continuously added as an aqueous solution to the amine and the catalyst.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3544510.6 | 1985-12-17 | ||
| DE19853544510 DE3544510A1 (en) | 1985-12-17 | 1985-12-17 | METHOD FOR PRODUCING ALIPHATIC TERTIA AMINES |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1266269A true CA1266269A (en) | 1990-02-27 |
Family
ID=6288597
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000525557A Expired - Fee Related CA1266269A (en) | 1985-12-17 | 1986-12-17 | Process for the preparation of aliphatic tertiary amines |
Country Status (4)
| Country | Link |
|---|---|
| CA (1) | CA1266269A (en) |
| DE (1) | DE3544510A1 (en) |
| GB (1) | GB2184119B (en) |
| SE (1) | SE8605290L (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105481698A (en) * | 2015-12-28 | 2016-04-13 | 江苏富淼科技股份有限公司 | Method for recovery of N,N-dimethyl-1,3-propylene diamine and coproduction of N,N,N',N'-tetramethyl-1,3-propylene diamine |
| CN108623474A (en) * | 2017-03-15 | 2018-10-09 | 汉鸿泰诺化学（上海）有限公司 | It is a kind of to purify N, N, N, the method for N- tetramethyl-1,3-propane diamines using azeotropic distillation |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3721539A1 (en) * | 1987-06-30 | 1989-01-12 | Ruhrchemie Ag | METHOD FOR PRODUCING METHYLAMINE |
| CN1075488C (en) * | 1998-09-10 | 2001-11-28 | 中国日用化学工业研究所 | Production method for preparing mono-alkyl dimethyl tertiary amine by use of aliphatic nitrile |
| CN112479892B (en) * | 2020-11-30 | 2022-10-18 | 江苏富淼科技股份有限公司 | Methylation method of polymethine propane diamine |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1932422A1 (en) * | 1969-06-26 | 1971-01-07 | Basf Ag | Process for the preparation of secondary or tertiary amines |
| DE2137710A1 (en) * | 1971-07-28 | 1973-02-08 | Basf Ag | PROCESS FOR HYDROGENATING NMETHYLATION OF AMINES |
-
1985
- 1985-12-17 DE DE19853544510 patent/DE3544510A1/en not_active Withdrawn
-
1986
- 1986-11-27 GB GB8628378A patent/GB2184119B/en not_active Expired - Fee Related
- 1986-12-10 SE SE8605290A patent/SE8605290L/en not_active Application Discontinuation
- 1986-12-17 CA CA000525557A patent/CA1266269A/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105481698A (en) * | 2015-12-28 | 2016-04-13 | 江苏富淼科技股份有限公司 | Method for recovery of N,N-dimethyl-1,3-propylene diamine and coproduction of N,N,N',N'-tetramethyl-1,3-propylene diamine |
| CN105481698B (en) * | 2015-12-28 | 2017-06-13 | 江苏富淼科技股份有限公司 | A kind of propane diamine of N, N dimethyl 1,3 reclaims the method with the propane diamine of coproduction N, N, N ', N ' tetramethyl 1,3 |
| CN108623474A (en) * | 2017-03-15 | 2018-10-09 | 汉鸿泰诺化学（上海）有限公司 | It is a kind of to purify N, N, N, the method for N- tetramethyl-1,3-propane diamines using azeotropic distillation |
Also Published As
| Publication number | Publication date |
|---|---|
| SE8605290D0 (en) | 1986-12-10 |
| GB8628378D0 (en) | 1986-12-31 |
| SE8605290L (en) | 1987-06-18 |
| GB2184119A (en) | 1987-06-17 |
| GB2184119B (en) | 1990-01-17 |
| DE3544510A1 (en) | 1987-06-19 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |